Monitoring the spatio–temporal dynamics of desertification in Huade County, Inner Mongolia based on Albedo–NDVI feature space

This paper is the result of environmental geological survey engineering.

Objective Land desertification is a global environmental problem, causing huge environmental damage and economic losses to the world every year. Arid and semi-arid areas are prone to desertification. As a representative of arid and semi-arid areas in northern China, the problem of land desertification in the central region of Inner Mongolia is typical and urgent. Therefore, it is particularly important to carry out dynamic monitoring of desertification in the region and analyze the driving factors of desertification development and change.

Methods This paper took 10 years as the time interval, used four Landsat series satellite images of Huade County from 1990 to 2020 as the data source, extracted NDVI and Albedo data, constructed Albedo–NDVI feature space, and analyzed the desertification degree, distribution characteristics and evolution law of land in Huade area. The driving factors of desertification evolution were further analyzed by collecting and analyzing the change trend of relevant data.

Results The linear model by fitting with the dry edge scatter points in the Albedo–NDVI feature space constructed in this study shows that the correlation between NDVI and Albedo is high, and the DDI index calculated by its fitting is better for evaluating the degree of desertification in Huade County. From 1990 to 2020, the development trend of desertification in Huade County have been divided into two stages: 1990–2010 is the stage of overall aggravation of desertification, and 2010–2020 is the stage of overall improvement of desertification. From 1990 to 2020, the area of increased desertification in the study area was greater than the area of improvement; the aggravation of desertification is mainly distributed in densely populated areas and near pastures, and the areas where desertification is improved are mainly distributed near seasonal nur. The driving factors of desertification development and change in Huade County mainly include: natural factors, human factors and policy factors.

Conclusions The DDI index calculated by Albedo–NDVI feature space fitting has a good effect on evaluating the degree of desertification in Huade County, and can effectively analyze the spatial and temporal changes and evolution trends of desertification. From 2010 to 2020, under a series of policies of ecological environment protection, desertification control and vegetation restoration, the desertification situation in the study area has improved to a certain extent.